1. Field of the Invention
The present invention relates to a substrate processing apparatus and a producing method of a semiconductor device, and more particularly to a wafer heating temperature control method and system in a semiconductor device producing apparatus and a producing method of a semiconductor device.
2. Description of the Related Art
Conventionally, when a wafer is heated in a RTP (Rapid Thermal Processing) apparatus which heats a wafer using radiation energy such as halogen lamp, with a constant such as PID of a temperature controlling system being set, a temperature-rise test is carried out a plurality of times so that a wafer temperature is not hunted or over/under shot when a temperature of the wafer is increased or stabilized, a temperature control parameter such as the PID constant is optimized and then, a product wafer is processed. In this case, if a kind of a wafer is different (for example, a kind of a film formed on a surface of a wafer is different), emissivity of a wafer heating surface is changed. Therefore, it is necessary to set a heating condition whenever a kind of the wafer is changed, which lowers productivity. Further, if a processing condition such as a processing pressure is changed, it is likewise necessary to set the heating condition.
In order to solve such problems, there is disclosed, in Japanese Patent Application Laid-open No. 11-32992, a method in which a substrate is once heated before it is processed, a temperature changing speed of the substrate caused by this heating operation is measured, a kind of the substrate is judged from a degree of this temperature changing speed, and based on this judging result, the substrate is processed in accordance with a control parameter table (a target temperature profile and a PID parameter) corresponding to the kind of the substrate.
In this method, however, it is necessary to once heat the substrate before it is processed, and there still is a problem that the productivity is deteriorated. Further, since the heating characteristics of the substrate are also changed when the substrate is heated during processing, there is a problem that the precision is deteriorated with only measurement before processing.